Expandable scaffold with cutting elements mounted thereto

ABSTRACT

A medical device assembly for incising a stenosis in a blood vessel which includes an incising device, a tubular sheath, and a catheter having an inflatable balloon mounted thereon. The incising device includes a self-expanding scaffold having a plurality of cutting elements projecting radially outward therefrom, and an elongate member extending proximally from the self-expanding scaffold to be manipulated by a user. The self-expanding scaffold is positionable in the lumen of the sheath in a contracted configuration and deployed out of the lumen of the sheath to permit the self-expanding scaffold to expand to an expanded configuration. The inflatable balloon of the catheter is configured to be advanced distally into an interior of the self-expanding scaffold through a proximal opening of the self-expanding scaffold, and inflation of the inflatable balloon urges the cutting elements radially outward to incise a stenosis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/571,552, filed on Aug. 10, 2012, which claims the benefit of U.S.Provisional Application No. 61/522,453, filed on Aug. 11, 2011, theentire disclosures of which are incorporated herein by reference.

TECHNICAL FIELD

The disclosure is directed to expandable scaffolds with cutting elementsmounted thereto to score or cut stenotic lesions in a blood vessel. Moreparticularly, the disclosure is directed to self-expanding scaffoldswith cutting elements mounted thereto and balloon catheters insertablewithin the scaffold to radially expand the cutting elements against astenotic lesion.

BACKGROUND

Heart and vascular disease are major problems in the United States andthroughout the world. Conditions such as atherosclerosis result in bloodvessels becoming blocked or narrowed. This blockage can result in lackof oxygenation of the heart, which has significant consequences sincethe heart muscle must be well oxygenated in order to maintain its bloodpumping action, or lack of oxygenation and/or circulation to otherregions of the body.

Occluded, stenotic, or narrowed blood vessels, as well as native orsynthetic arteriovenous dialysis fistulae, may be treated in arecanalization procedure, such as with an angioplasty balloon catheteradvanced over a guidewire to an occlusion so that the balloon ispositioned across the occlusion. The balloon is then inflated to enlargethe passageway through the occlusion.

One of the major obstacles in treating coronary artery disease and/ortreating blocked blood vessels or fistulae is re-stenosis orre-narrowing of the passageway through the occlusion subsequent to anangioplasty procedure or other recanalization procedure. Evidence hasshown that cutting or scoring the stenosis, for example, with anangioplasty balloon equipped with a cutting element, during treatmentcan reduce incidence of re-stenosis. Additionally, cutting or scoringthe stenosis may reduce trauma at the treatment site and/or may reducethe trauma to adjacent healthy tissue. Cutting elements may also bebeneficial additions to angioplasty procedures when the targetedocclusion is hardened, fibrotic or calcified. It is believed typicalangioplasty balloons, alone, may not be able to expand certain of thesehardened lesions. Thus, angioplasty balloons equipped with cuttingelements having cutting edges have been developed to attempt to enhanceangioplasty treatments. Existing cutting elements tend to be fairlyrigid. The rigid structure of the cutting elements limits theflexibility of the balloon, thereby limiting the ability of the cuttingelement, and the balloon to which it is mounted, to navigate through atortuous vasculature of a patient.

Accordingly, there is an ongoing need for delivering cutting elementsfor use in angioplasty treatments, and methods of incising a stenosiswith cutting elements provided with a medical device. Namely, it wouldbe desirable to provide an expandable structure for use with anangioplasty balloon to position cutting elements proximate a stenoticlesion that is flexible for navigating tortuous anatomy.

SUMMARY

The disclosure is directed to several alternative designs, materials andmethods of manufacturing medical device structures and assemblies, andthe uses thereof.

Accordingly, one illustrative embodiment is a medical device assemblyfor incising a stenosis in a blood vessel. The medical device assemblyincludes a self-expanding scaffold configured to be expandable from afirst contracted configuration to a second expanded configuration. Theself-expanding scaffold is biased toward the second expandedconfiguration. A cutting element is secured to the self-expandingscaffold and extends radially outward therefrom. The assembly furtherincludes a sheath having a lumen therein. The self-expanding scaffold ispositionable in the lumen of the sheath in the first contractedconfiguration. An elongate member extends proximally from theself-expanding scaffold through the lumen of the sheath. Theself-expanding scaffold is constrained in the lumen of the sheath tomaintain the self-expanding scaffold in the first contractedconfiguration and deployed out of the lumen of the sheath to permit theself-expanding scaffold to expand to the second expanded configuration.

Another illustrative embodiment is a medical device assembly forincising a stenosis in a blood vessel. The medical device assemblyincludes an incising device, a tubular sheath, and a catheter having aninflatable balloon mounted thereon. The incising device includes anexpandable scaffold having a plurality of cutting elements projectingradially outward therefrom, and an elongate member extending proximallyfrom the expandable scaffold to be manipulated by a user. The expandablescaffold is positionable in the lumen of the tubular sheath in acontracted configuration with the plurality of cutting elements engagedwith an interior of the tubular sheath. The inflatable balloon of thecatheter is configured to be advanced distally into an interior of theexpandable scaffold through a proximal opening of the expandablescaffold, and inflation of the inflatable balloon urges the cuttingelements radially outward to incise a stenosis.

Yet another illustrative embodiment is a method of incising a stenosisin a blood vessel. The method includes advancing a self-expandingscaffold of an incising device in a contracted configuration within alumen of a tubular sheath to a stenosis in a blood vessel. Theself-expanding scaffold includes a plurality of cutting elementsprojecting radially outward therefrom. The tubular sheath is withdrawnfrom the self-expanding scaffold to permit the self-expanding scaffoldto automatically expand radially outward to an expanded configuration tourge the cutting elements against the stenosis. A deflated balloon of aballoon catheter is advanced into an interior of the self-expandingscaffold through a proximal opening of the self-expanding scaffold withthe self-expanding scaffold in the expanded configuration. The balloonis then inflated to press against the interior of the self-expandingscaffold and press the cutting elements into the stenosis.

The above summary of some example embodiments is not intended todescribe each disclosed embodiment or every implementation of theaspects of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The aspects of the disclosure may be more completely understood inconsideration of the following detailed description of variousembodiments in connection with the accompanying drawings, in which:

FIG. 1 is a side view of an exemplary system with cutting elements forincising a stenotic lesion;

FIG. 1A is a cross-sectional view of the cutting device of FIG. 1 takenalong line 1A-1A;

FIG. 1B is a side view of an alternative arrangement of cutting elementsmounted on the incising device of FIG. 1;

FIG. 2 is a side view of another exemplary system with cutting elementsfor incising a stenotic lesion;

FIG. 2A is a cross-sectional view of the cutting device of FIG. 2 takenalong line 2A-2A;

FIG. 3 is a side view of another exemplary system with cutting elementsfor incising a stenotic lesion;

FIG. 3A is a cross-sectional view of the cutting device of FIG. 3 takenalong line 3A-3A;

FIGS. 4-8 illustrate an exemplary method of treating a stenotic lesionwith an expandable scaffold with cutting elements in cooperation with aninflatable balloon of a balloon catheter;

FIG. 9 is a side view of another exemplary system with cutting elementsfor incising a stenotic lesion;

FIG. 9A is a cross-sectional view of the cutting device of FIG. 9 takenalong line 9A-9A; and

FIGS. 10-14 illustrate an exemplary method of treating a stenotic lesionwith the incising system of FIG. 9.

While the aspects of the disclosure are amenable to variousmodifications and alternative forms, specifics thereof have been shownby way of example in the drawings and will be described in detail. Itshould be understood, however, that the intention is not to limitaspects of the disclosure to the particular embodiments described. Onthe contrary, the intention is to cover all modifications, equivalents,and alternatives falling within the spirit and scope of the disclosure.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about”, whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the term “about” may be indicative asincluding numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4,and 5).

Although some suitable dimensions, ranges and/or values pertaining tovarious components, features and/or specifications are disclosed, one ofskill in the art, incited by the present disclosure, would understanddesired dimensions, ranges and/or values may deviate from thoseexpressly disclosed.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The detailed description and the drawings, which are notnecessarily to scale, depict illustrative embodiments and are notintended to limit the scope of the disclosure. The illustrativeembodiments depicted are intended only as exemplary. Selected featuresof any illustrative embodiment may be incorporated into an additionalembodiment unless clearly stated to the contrary.

FIG. 1 is a side view of an exemplary medical device assembly 10 forincising a stenosis in a blood vessel, or other lesion in an anatomicalpassage. The medical device assembly 10 may include an incising device12 including one or more, or a plurality of cutting elements 20 forincising or scoring a stenosis within a blood vessel. FIG. 1A is across-sectional view taken along line 1A-1A of FIG. 1, furtherillustrating various features of the incising device 12. The medicaldevice assembly 10 may also include a tubular sheath 34 for deliveringthe incising device 12 to the stenotic lesion in the blood vessel and/orwithdrawing the incising device 12 from the blood vessel in a radiallycontracted configuration.

The incising device 12 may include an expandable scaffold 14 carryingthe one or more, or plurality of cutting elements 20 thereon. In someinstances, the expandable scaffold 14 may be a self-expanding scaffold14 configured to automatically radially expand from a first, contractedconfiguration when radially constrained to a second, radially expandedconfiguration when unconstrained. Thus, the self-expanding scaffold 14may be biased to the radially expanded configuration such that theself-expanding scaffold 14 tends to automatically return to the expandedconfiguration when all radially constraining forces are removed. Inother instances, the expandable scaffold 14 may be expanded from afirst, radially contracted configuration to a second radially expandedconfiguration through the application of an expansion force exerted byan expandable member, an expandable linkage, or other actuatablestructure for expanding the scaffold 14.

The expandable scaffold 14 may be formed from any number ofbiocompatible materials, including polymeric materials, metals, andmetal alloys, such as stainless steel, tantalum, or a nickel titaniumalloy such as a superelastic nickel titanium alloy known as Nitinol,which may have shape memory properties in some instances.

The expandable scaffold 14 may have any desired construction permittingthe expandable scaffold 14 to be radially compressed into the contractedconfiguration for positioning in the lumen 38 of the sheath 34, yetpermitting the expandable scaffold 14 to radially expand to the expandedconfiguration when unconstrained by the sheath 34. In some instances,the expandable scaffold 14 may be formed of a plurality ofinterconnected struts, filaments, wires or other expandable framework.For example, as shown in FIG. 1, the expandable scaffold 14 may includea plurality of filaments or wires 16 helically wound into a generallytubular construct. A first subset of the wires 16 may be helically woundin a first direction, while a second subset of the wires 16 may behelically wound in a second, opposite direction. The wires 16 mayintersect or cross one another at cross-over points 18. In someinstances, the wires 16 may be secured or attached to one another at thecross-over points 18, or the wires 16 may be unsecured and free to moverelative to one another at the cross-over points 18.

The proximal end of the expandable scaffold 14 may include a proximalopening 28 opening into the interior of the expandable scaffold 14,allowing access to the interior of the expandable scaffold 14 to permitintroducing and positioning a balloon of a balloon catheter therein. Insome instances, the expandable scaffold 14 may include an annular hoopat the proximal end to define the proximal opening 28 into the interiorof the expandable scaffold 14. The annular hoop may be formed with oneor more of the wires 16, or from a discrete member to which the wires 16may be attached to. In other instances, the proximal opening 28 may bedefined by the collective circumferential arrangement of the proximalends of the wires 16.

The proximal portion of the expandable scaffold 14 may taper radiallyinward in a proximal direction to facilitate advancing the sheath 34back over the expandable scaffold 14 to radially contract the expandablescaffold 14 after use of the incising device 12. For instance, theproximal end of the expandable scaffold 14 may have a diameter less thanthe inner diameter of the sheath 34 such that the sheath 34 may surroundthe proximal tapered portion as the expandable scaffold 14 is drawn intothe lumen 38 of the sheath 34. In some instances, the expandablescaffold 14 may include one or more proximally extending struts 22 toguide the sheath 34 over the expandable scaffold 14 when collapsing theexpandable scaffold 14 in the sheath 34 subsequent to using the incisingdevice 12.

The distal end of the helically arranged wires 16 forming the expandablescaffold 14 may converge in a distal direction to a distal tip 24. Asshown in FIG. 1A, the wires 16 may extend through an arcuate pathway asthe wires taper toward the distal tip 24 from the cylindrical portion ofthe expandable scaffold 14. In some instances, the distal tip 24 may beconstructed of one or more of the wires 16, such as one or more of thewires 16 tightly wound into a coil. In other embodiments, the distal tip24 may be formed of a discrete tubular member to which the distal endsof the wires 16 may be secured to. The distal tip 24 may be a tubularconstruction having a lumen 26 extending therethrough for the passage ofa guidewire 30. Thus, a guidewire 30 may be disposed in the lumen 26 ofthe distal tip 24, such that the expandable scaffold 14 of the incisingdevice 12 may be advanced over the guidewire 30 to a treatment site. Insome instances, the distal tip 24, and thus the guidewire 30 extendingthrough the central lumen 26 of the distal tip 24, may be arrangedcoaxially with the expandable scaffold 14, such that a balloon of aballoon catheter advanced over the guidewire 30 into the interior of theexpandable scaffold 14 is coaxially positioned within the expandablescaffold 14.

The cutting elements 20 may vary in number, position, and arrangementabout the expandable scaffold 14. For example, the incising device 12may include one, two, three, four, five, six, or more cutting elements20 that are disposed at any position along the expandable scaffold 14and in a regular, irregular, or any other suitable pattern. For example,in some embodiments the incising device 12 may include a plurality ofcutting elements 20 longitudinally arranged symmetrically around thecircumference of the expandable scaffold 14.

In some instances, the cutting elements 20 may include multiple cuttingsegments with flexible regions 19 between adjacent segments to increasethe flexibility of the cutting elements 20. In some instances, adjacentsegments of the cutting elements 20 may be interconnected with aflexible link, while in other instances adjacent segments of the cuttingelements 20 may be spaced from one another at the flexible regions 19.

In some instances, such as shown in FIG. 1B, the incising device 12 mayinclude a plurality of cutting elements 20 off-set from one anotheraround the circumference of the expandable scaffold 14. For example, theincising device 12 may include one or more, or a plurality of cuttingelements 20 radially offset from, as well as longitudinally offset fromone or more, or a plurality of adjacent cutting elements 20. Thus, thecutting elements 20 may be staggered both radially and longitudinallyaround the circumference of the expandable scaffold 14.

The cutting elements 20 may be made from any suitable material such as ametal, metal alloy, polymer, metal-polymer composite, and the like, orany other suitable material. For example, cutting elements 20 may bemade from stainless steel, titanium, nickel-titanium alloys, tantalum,iron-cobalt-nickel alloys, or other metallic materials in someinstances.

As shown in FIG. 1, the cutting elements 20 may be mounted to andproject radially outward from the expandable scaffold 14. In otherembodiments, the wires 16 of the expandable scaffold 14 may define thecutting elements 20 for scoring or cutting tissue. The cutting elements20 may be secured to the wires 16 of the expandable scaffold 14 such asby welding, brazing, soldering, crimping, adhesively bonding, thermalbonding, or other desired means. In some instances, the cutting elements20 may be secured to the expandable scaffold 14 at one or more of thecross-over points 18 of the wires 16. In some embodiments, it may bedesirable to secure the opposing ends of the cutting elements 20 towires 16 of the expandable scaffold 14, such as at cross-over points 18of the wires 16.

The cutting elements 20 may be secured to the generally cylindricalportion of the expandable scaffold 14, such that the cutting elements 20may extend in a generally longitudinal direction parallel to the centrallongitudinal axis of the expandable scaffold 14. In other instances, thecutting elements 20 may be helically arranged around the circumferenceof the expandable scaffold 14, or arranged in another desiredconfiguration. The cutting elements 20 may extend any desired extent ofthe expandable scaffold 14. For example, the cutting elements 20 may besecured intermediate the proximal and distal extents of the generallycylindrical portion of the expandable scaffold 14.

As described later herein, a balloon 52, or other radially expandablemember of a catheter 50 may be positioned in the interior of theexpandable scaffold 14 to provide a radially outward force to urge thecutting elements 20 radially outward and press the cutting elements 20against a stenosis or other tissue. In some instances, a balloon of acatheter may be integrally incorporated with the incising device 12, andthus pre-inserted within the expandable scaffold 14 of the incisingdevice 12 prior to using the incising device 12 in a medical procedure.In other instances, however, the incising device 12 may be providedwithout a balloon 52 pre-inserted within the expandable scaffold 14,thus allowing a physician to select any desired balloon 52 or otherradially expandable member of a catheter 50 to be inserted within theexpandable scaffold 14 intra-operatively, and/or allow for exchangingbetween a plurality of different sizes of balloons 52 intra-operatively.

The incising device 12 may also include an elongate member 32 extendingproximally from the expandable scaffold 14 to be manipulated by aphysician during a medical procedure. The elongate member 32 may havesufficient rigidity to be pushed distally (e.g., apply an axiallycompressive force) and pulled proximally (e.g., apply an axially tensileforce) to manipulate the expandable scaffold 14. The elongate member 32,which may be a tubular member or a solid member in some instances, mayhave a length sufficient to extend from the treatment site to a handleassembly (not shown) of the medical device assembly 10 located externalof the patient such that medical personnel can actuate the elongatemember 32 to manipulate the expandable scaffold 14. For example, theelongate member 32 may extend through the lumen 38 of the tubular sheath34 adjacent to and generally parallel to the guidewire 30 to a handleassembly of the sheath 34. The elongate member 32 may be non-coaxiallyconnected to the expandable scaffold 14, such as attached to theexpandable scaffold 14 at a peripheral location offset from the centrallongitudinal axis of the expandable scaffold 14, and thus offset fromthe guidewire 30. In some instances, one or more struts 22 may extendfrom the expandable scaffold 14 to the elongate member 32.

The sheath 34 may be a tubular member having a lumen 38 extendingtherethrough opening out at a distal opening 36 of the tubular sheath34. The lumen 38 of the sheath 34 may have an inner diameter sized toreceive the expandable scaffold 14 therein in the radially contractedconfiguration. The expandable scaffold 14 may be positioned in the lumen38 of the tubular sheath 34 in the contracted configuration with thecutting elements 20 engaged with an interior surface of the tubularsheath 34. The elongate member 32 may extend proximally through thelumen 38 to the proximal end of the sheath 34. Likewise, the guidewire30 may extend through the lumen 38 of the sheath 34 along an exteriorsurface of the elongate member 32.

While the sheath 34 may be formed of a flexible polymeric tubing fornavigating a vasculature, the sheath 34 may include a protective distaltip 40 configured to withstand scoring from the cutting elements 20 asthe incising device 12 is advanced out of the lumen 38 through thedistal opening 36 and/or withdrawn into the lumen 38 through the distalopening 36. For instance, the protective distal tip 40 may include ametal annular band, a tubular braid member, a helical coil, or otherreinforcing structure providing the protective distal tip 40 sufficientrigidity to withstand cutting forces exerted on the protective distaltip 40 from contact with the cutting elements 20. In other instances,the protective distal tip 40 may include an impact resistant polymerhaving a hardness or durability sufficient to withstand cutting forcesexerted on the protective distal tip 40 from contact with the cuttingelements 20.

FIG. 2 is a side view of another exemplary medical device assembly 110for incising a stenosis in a blood vessel, or other lesion in ananatomical passage. The medical device assembly 110 may include anincising device 112 including one or more, or a plurality of cuttingelements 120 for incising or scoring a stenosis within a blood vessel.FIG. 2A is a cross-sectional view taken along line 2A-2A of FIG. 2,further illustrating various features of the incising device 112.Similar to the medical device assembly 10 of FIG. 1, the medical deviceassembly 110 may also include a tubular sheath 34 for delivering theincising device 112 to the stenotic lesion in the blood vessel and/orwithdrawing the incising device 112 from the blood vessel.

The incising device 112 may be similar to the incising devise 12 in manyrespects. For example, the incising device 112 may include an expandablescaffold 114 carrying the one or more, or plurality of cutting elements120 thereon, and be configured to radially expand from a first,contracted configuration when radially constrained to a second, radiallyexpanded configuration when unconstrained. In some instances, theexpandable scaffold 114 may be a self-expanding scaffold 114 configuredto automatically radially expand from the first, contractedconfiguration when radially constrained to the second, radially expandedconfiguration when unconstrained. Thus, the self-expanding scaffold 114may be biased to the radially expanded configuration such that theself-expanding scaffold 114 tends to automatically return to theexpanded configuration when all radially constraining forces areremoved. In other instances, the expandable scaffold 114 may be expandedfrom the first, radially contracted configuration to the second radiallyexpanded configuration through the application of an expansion forceexerted by an expandable member, an expandable linkage, or otheractuatable structure for expanding the scaffold 114.

The expandable scaffold 114 may have any desired construction permittingthe expandable scaffold 114 to be radially compressed into thecontracted configuration for positioning in the lumen 38 of the sheath34, yet permitting the expandable scaffold 114 to radially expand to theexpanded configuration when unconstrained by the sheath 34. For example,as shown in FIG. 2, the expandable scaffold 114 may include a pluralityof filaments or wires 116 helically wound with a first wire 116helically wound in a first direction and a second wire 116 helicallywound in a second, opposite direction. The wires 116 may intersect orcross one another at cross-over points 118. In some instances, the wires116 may be secured or attached to one another at the cross-over points118, or the wires 116 may be unsecured and free to move relative to oneanother at the cross-over points 118. The incising device 112 may alsoinclude an elongate member 132 extending proximally from the expandablescaffold 114 through the lumen 38 of the sheath 34 to be manipulated bya physician during a medical procedure. In some instances, the elongatemember 132 may be formed as a proximal extension of one or more of thewires 116 or as a discrete member secured to the proximal ends of thewires 116, for example.

The expandable scaffold 114 may include a proximal opening 128 openinginto the interior of the expandable scaffold 114, allowing access to theinterior of the expandable scaffold 114 to permit introducing andpositioning a balloon of a balloon catheter therein. In some instances,the proximal opening 128 may be defined by the proximal most arcuatewinding of the wires 116 from the elongate member 132 to the firstproximal most cross-over point 118 of the wires 116.

The distal end of the helically arranged wires 116 forming theexpandable scaffold 114 may terminate at a distal tip 124. As shown inFIG. 2A, the wires 116 may extend through an arcuate pathway of asmaller radius of curvature as the wires taper toward the distal tip 124from the cylindrical portion of the expandable scaffold 114. Similar tothe distal tip 24, the distal tip 124 may be constructed of one or moreof the wires 116, or the distal tip 124 may be formed of a discretetubular member to which the distal ends of the wires 116 may be securedto, having a lumen 126 extending therethrough for the passage of aguidewire 30. In some instances, the distal tip 124, and thus theguidewire 30 extending through the central lumen 126 of the distal tip124, may be arranged coaxially with the expandable scaffold 114, suchthat a balloon of a balloon catheter advanced over the guidewire 30 intothe interior of the expandable scaffold 114 is coaxially positionedwithin the expandable scaffold 114.

The cutting elements 120 may vary in number, position, and arrangementabout the expandable scaffold 114. For example, the incising device 112may include one, two, three, four, five, six, or more cutting elements120 that are disposed at any position along the expandable scaffold 114and in a regular, irregular, or any other suitable pattern. For example,in some embodiments the incising device 112 may include a plurality ofcutting elements 120 longitudinally arranged symmetrically around thecircumference of the expandable scaffold 114.

As shown in FIG. 2, the cutting elements 120 may be mounted to andproject radially outward from the expandable scaffold 114. In otherembodiments, the wires 116 of the expandable scaffold 114 may define thecutting elements 120 for scoring or cutting tissue.

As shown in FIG. 2, in some instances, the cutting elements 120 may bemounted to the expandable scaffold 114 such that the wires 116 may betranslatable relative to the cutting elements 120. For example, thecutting elements 120 may include grommets or collars 122 through whichthe wires 116 slidably extend through, allowing the cutting elements 120to float on the wires 116. In such instances, the expandable scaffold114 may be collapsed by longitudinally extending the wires 116 such thatthe connection between the cutting elements 120 and the wires 116 at thecollars 122 translates along the wires 116 as the wires 116 areelongated. In some instances, the cutting elements 120 may be configuredsuch that a cutting edge of the cutting element 120 is oriented radiallyoutward to contact a vessel wall or stenosis regardless of therotational orientation of the cutting element 120 about its longitudinalaxis.

In other instances, the cutting elements 120 may be secured to the wires116 of the expandable scaffold 114 such as by welding, brazing,soldering, crimping, adhesively bonding, thermal bonding, or otherdesired means. In some instances, the cutting elements 120 may besecured to the cylindrical portion of the expandable scaffold 114 at oneor more of the cross-over points 118 of the wires 116. In someembodiments, it may be desirable to secure the opposing ends of thecutting elements 120 to wires 116 of the expandable scaffold 114, suchas at cross-over points 118 of the wires 116. For example, a firstcutting element 120 may have a proximal end secured to the wires 116 atthe proximal terminus of the expandable scaffold 114 and a distal endsecured to the wires 116 at a cross-over point 118 distal of theproximal terminus of the expandable scaffold 114. A second cuttingelement 120, which may be secured to the expandable scaffold 114 on anopposite side of the expandable scaffold as the first cutting element120, may have a proximal end secured to a proximal cross-over point 118and a distal end secured to a distal cross-over point 118. The firstcutting element 120 may be offset longitudinally from the first cuttingelement 120 as the securement locations (e.g., cross-over points 118) onopposite sides of the expandable scaffold 114 may be alternatelyarranged axially along the expandable scaffold 114.

As described later herein, a balloon 52, or other radially expandablemember of a catheter 50 may be positioned in the interior of theexpandable scaffold 114 to provide a radially outward force to urge thecutting elements 120 radially outward and press the cutting elements 120against a stenosis or other tissue. In some instances, a balloon of acatheter may be integrally incorporated with the incising device 112,and thus pre-inserted within the expandable scaffold 114 of the incisingdevice 112 prior to using the incising device 112 in a medicalprocedure. In other instances, however, the incising device 112 may beprovided without a balloon 52 pre-inserted within the expandablescaffold 114, thus allowing a physician to select any desired balloon 52or other radially expandable member of a catheter 50 to be insertedwithin the expandable scaffold 114 intra-operatively, and/or allow forexchanging between a plurality of different sizes of balloons 52intra-operatively.

FIG. 3 is a side view of another exemplary medical device assembly 210for incising a stenosis in a blood vessel, or other lesion in ananatomical passage. The medical device assembly 210 may include anincising device 212 including one or more, or a plurality of cuttingelements 220 for incising or scoring a stenosis within a blood vessel.FIG. 3A is a cross-sectional view taken along line 3A-3A of FIG. 3,further illustrating various features of the incising device 212.Similar to the medical device assembly 10 of FIG. 1, the medical deviceassembly 210 may also include a tubular sheath 34 for delivering theincising device 212 to the stenotic lesion in the blood vessel and/orwithdrawing the incising device 212 from the blood vessel.

The incising device 212 may be similar to the incising devise 12 in manyrespects. For example, the incising device 212 may include an expandablescaffold 214 carrying the one or more, or plurality of cutting elements220 thereon, and be configured to radially expand from a first,contracted configuration when radially constrained to a second, radiallyexpanded configuration when unconstrained. In some instances, theexpandable scaffold 214 may be a self-expanding scaffold 214 configuredto automatically radially expand from the first, contractedconfiguration when radially constrained to the second, radially expandedconfiguration when unconstrained. Thus, the self-expanding scaffold 214may be biased to the radially expanded configuration such that theself-expanding scaffold 214 tends to automatically return to theexpanded configuration when all radially constraining forces areremoved. In other instances, the expandable scaffold 214 may be expandedfrom the first, radially contracted configuration to the second radiallyexpanded configuration through the application of an expansion forceexerted by an expandable member, an expandable linkage, or otheractuatable structure for expanding the scaffold 214.

The expandable scaffold 214 may have any desired construction permittingthe expandable scaffold 214 to be radially compressed into thecontracted configuration for positioning in the lumen 38 of the sheath34, yet permitting the expandable scaffold 214 to radially expand to theexpanded configuration when unconstrained by the sheath 34. For example,as shown in FIG. 3, the expandable scaffold 214 may include a pluralityof struts 216 extending longitudinally along the expandable scaffold214. The struts 216, which may be wires or other filaments in someinstances, may be circumferentially arranged uniformly or nonuniformlyaround the circumference of the expandable scaffold 214. The incisingdevice 212 may also include an elongate member 232 extending proximallyfrom the expandable scaffold 214 through the lumen 38 of the sheath 34to be manipulated by a physician during a medical procedure. In someinstances, the elongate member 232 may be formed as a proximal extensionof one or more of the struts 216 or as a discrete member secured to theexpandable scaffold 214, for example. A one or more, or a plurality ofadditional extension wires 222 may extend from the expandable scaffold214 to the elongate member 232, providing a tapered transition from theelongate member 232 to struts 216 of the expandable scaffold 214 tofacilitate drawing the expandable scaffold 214 into the sheath 34. Insome instances, the proximally extending extension wires 222 may beunitarily formed from the struts 216, or the extension wires 222 may bediscrete members extending between the elongate member 232 and thestruts 216. The circumferentially arranged extension wires 222 maydefine a proximal opening 228 opening into the interior of theexpandable scaffold 214, allowing access to the interior of theexpandable scaffold 214 to permit introducing and positioning a balloonof a balloon catheter therein. The proximal tapered portion provided bythe extension wires 222 may facilitate positioning the sheath 34 backover the expandable scaffold 214 to radially contract the expandablescaffold 214 after use of the incising device 212. For instance, the oneor more proximally extending extension wires 222 may help guide thesheath 34 over the expandable scaffold 214 when collapsing theexpandable scaffold 214 in the sheath 34 subsequent to using theincising device 212.

The longitudinal struts 216 may extend axially to define a cylindricalportion of the expandable scaffold 214, and then taper radially inwardnear the distal end of the expandable scaffold 214 to converge at adistal tip 224. The distal tip 224 may be a tubular member having alumen 226 extending therethrough for the passage of a guidewire 30. Insome instances such as shown in FIG. 3A, the distal tip 224, and thusthe guidewire 30 extending through the central lumen 226 of the distaltip 224, may be arranged coaxially with the expandable scaffold 214,such that a balloon of a balloon catheter advanced over the guidewire 30into the interior of the expandable scaffold 214 is coaxially positionedwithin the expandable scaffold 214.

The cutting elements 220 may vary in number, position, and arrangementabout the expandable scaffold 214. For example, the incising device 212may include one, two, three, four, five, six, or more cutting elements220 that are disposed at any position along the expandable scaffold 214and in a regular, irregular, or any other suitable pattern. For example,in some embodiments the incising device 212 may include a plurality ofcutting elements 220 longitudinally arranged symmetrically around thecircumference of the expandable scaffold 214.

As shown in FIG. 3, the cutting elements 220 may be mounted to andproject radially outward from the struts 216 of the expandable scaffold214. In other embodiments, the struts 216 of the expandable scaffold 214may define the cutting elements 220 for scoring or cutting tissue. Thecutting elements 220 may be secured to the struts 216 of the expandablescaffold 214 such as by welding, brazing, soldering, crimping,adhesively bonding, thermal bonding, or other desired means.

As described later herein, a balloon 52, or other radially expandablemember of a catheter 50 may be positioned in the interior of theexpandable scaffold 214 to provide a radially outward force to urge thecutting elements 220 radially outward and press the cutting elements 220against a stenosis or other tissue. In some instances, a balloon of acatheter may be integrally incorporated with the incising device 212,and thus pre-inserted within the expandable scaffold 214 of the incisingdevice 212 prior to using the incising device 212 in a medicalprocedure. In other instances, however, the incising device 212 may beprovided without a balloon 52 pre-inserted within the expandablescaffold 214, thus allowing a physician to select any desired balloon 52or other radially expandable member of a catheter 50 to be insertedwithin the expandable scaffold 214 intra-operatively, and/or allow forexchanging between a plurality of different sizes of balloons 52intra-operatively.

FIGS. 4-8 illustrate an exemplary method of treating a stenotic lesionwith an expandable scaffold with cutting elements in cooperation with aninflatable balloon of a balloon catheter. Although the exemplary methodwill be described in regards to using the incising device 12, it isunderstood that such a method of treating a stenosis may be performedusing the incising device 112 described in FIG. 2, the incising device212 described in FIG. 3, or a similarly configured incising device inaccordance with this disclosure.

The medical device assembly 10 may be navigated through the lumen 92 ofa blood vessel 90 to a treatment location proximate a stenosis 94 orother tissue to be treated which may be within any suitable peripheralor cardiac vessel lumen location. For instance, the incising device 12may be loaded in the sheath 34 with the expandable scaffold 14constrained in the contracted position within the lumen 38 of the sheath34 prior to advancing the medical device assembly 10 through the bloodvessel 90. Alternatively, the sheath 34 may be initially placedproximate the stenosis 94, and subsequently the incising device 12 maybe inserted into the lumen 38 and pushed distally through the sheath 34to the treatment site.

The distal tip 24 of the incising device 12 may be inserted over aguidewire 30, with the guidewire 30 extending through the interior ofthe expandable scaffold 14 and through the lumen 38 of the sheath 34. Asshown in FIG. 4, the expandable scaffold 14 of the incising device 12may be advanced in the contracted configuration over the guidewire 30while constrained within the lumen 38 of the tubular sheath 34 to thestenosis 94 in the blood vessel 90. The guidewire 30 may extend alongand adjacent to the elongate member 32 of the incising device 12 withinthe lumen 38 of the sheath 34.

As shown in FIG. 5, with the radially constrained expandable scaffold 14positioned across the stenosis 94 within the sheath 34, the sheath 34may be withdrawn proximally to deploy the expandable scaffold 14distally from the distal opening 36 of the tubular sheath 34. Forexample, the physician may hold the elongate member 32 of the incisingdevice 12 while pulling the sheath 34 proximally to maintain theexpandable scaffold 14 in a desired position as the sheath 34 iswithdrawn. Alternatively, the physician may push the elongate member 32distally while holding the sheath 34 to expel the expandable scaffold 14from the distal opening 36 of the sheath 34. The protective distal tip40 of the sheath 34 may withstand scoring from the cutting elements 20as the incising device 12 is advanced out of the lumen 38 through thedistal opening 36. Once unconstrained by the sheath 34, the expandablescaffold 14 may automatically radially expand toward the expandedconfiguration. The expandable scaffold 14 may be sized such that in theexpanded configuration, the cutting elements 20 may contact and/or pressagainst the stenosis 94.

As shown in FIG. 6, a deflated balloon 52, or other expandable member,of a catheter 50 (if not already disposed in the interior of theexpandable scaffold 14 prior to deploying the incising device 12 acrossthe stenosis 94) may be advanced distally over the guidewire 30 throughthe proximal opening 28 into the interior of the expandable scaffold 14with the expandable scaffold 14 in the expanded configuration. Thecatheter 50 may be selected by the physician based on the desiredinflated diameter of the balloon 52 for a particular medical procedure.For example, the balloon 52 chosen may be selected based on the diameterof the vessel to be treated, the size of the stenosis, and/or the amountof radial expansion of the expandable scaffold 14 desired. In someinstances, the catheter 50 may be advanced over the guidewire 30 throughthe lumen 38 of the sheath 34, or the sheath 34 may be completelywithdrawn from the patient prior to advancing the catheter 50 over theguidewire 30.

In some instances, the balloon 52 may be formed of a compliant material,a semi-compliant material, or a non-compliant material. The balloon 52may be made from typical angioplasty balloon materials includingpolymers such as polyethylene terephthalate (PET),polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE),polybutylene terephthalate (PBT), polyurethane, polyvinylchloride (PVC),polyether-ester, polyester, polyamide, elastomeric polyamides, polyetherblock amide (PEBA), as well as other suitable materials, or mixtures,combinations, copolymers thereof, polymer/metal composites, and thelike. The balloon 52 may be configured so that the balloon 52 includesone or more “wings” or wing-shaped regions when the balloon 52 isdeflated.

The catheter 50 may include a catheter shaft 54 secured to the balloon52 and extending proximally therefrom. The catheter shaft 54 may besimilar to typical catheter shafts. For example, the catheter shaft 54may include an outer tubular member and an inner tubular memberextending through at least a portion of the outer tubular member. Thetubular members may be arranged in any appropriate way. For example, insome embodiments the inner tubular member can be disposed coaxiallywithin the outer tubular member. Alternatively, the inner tubular membermay follow the inner wall or otherwise be disposed adjacent the innerwall of the outer tubular member. In other embodiments, the tubularmembers may be arranged in another desired fashion.

The inner tubular member may include an inner lumen, such as a guidewirelumen for receiving the guidewire 30 therethrough. Accordingly, thecatheter 50 can be advanced over the guidewire 30 to the desiredlocation. The guidewire lumen may extend along essentially the entirelength of the catheter shaft 54 such that catheter 50 resemblestraditional “over-the-wire” catheters. Alternatively, the guidewirelumen may extend along only a portion of the catheter shaft 54 such thatthe catheter 50 resembles “single-operator-exchange” or “rapid-exchange”catheters.

The catheter shaft 54 may also include an inflation lumen that may beused, for example, to transport inflation media to and from the balloon52 to selectively inflate and/or deflate the balloon 52. The locationand position of the inflation lumen may vary, depending on theconfiguration of the tubular members of the catheter shaft 54. Forexample, when the outer tubular member surrounds the inner tubularmember, the inflation lumen may be defined within the space between thetubular members. In embodiments in which the outer tubular member isdisposed alongside the inner tubular member, then the inflation lumenmay be the lumen of the outer tubular member.

The balloon 52 may be coupled to the catheter shaft 54 in any of anumber of suitable ways. For example, the balloon 52 may be adhesivelyor thermally bonded to the catheter shaft 54. In some embodiments, aproximal waist of the balloon 52 may be bonded to the catheter shaft 54,for example, bonded to the distal end of the outer tubular member, and adistal waist of the balloon 52 may be bonded to the catheter shaft 54,for example, bonded to the distal end of the inner tubular member. Theexact bonding positions, however, may vary.

In some instances, the catheter 50 may be properly positioned within theinterior of the expandable scaffold 14 when the distal tip 56 of thecatheter 50 contacts a proximal end of the distal tip 24 of the incisingdevice 12. As the balloon 52 and catheter 50 may be advanced over theguidewire 30, which extends centrally through the expandable scaffold14, the balloon 52 may likewise be concentrically positioned within theinterior of the expandable scaffold 14.

As shown in FIG. 7, once positioned within the interior of theexpandable scaffold 14, the balloon 52 can be inflated to exert aradially outward force on the interior of the expandable scaffold 14 tofurther enlarge the expandable scaffold 14 and/or to urge the cuttingelements 20 further radially outward to penetrate into or score thestenosis 94. Thus, the cutting elements 20 may cut or score the stenosis94 to facilitate enlarging the lumen proximate the stenosis 94.

Subsequently, the balloon 52 may be deflated and withdrawn proximallyfrom the interior of the expandable scaffold 14 through the proximalopening 28 of the expandable scaffold 14 with the expandable scaffold 14in the expanded configuration. In some instances, it may be desirable toadvance a second balloon of a second balloon catheter over the guidewire30 into the interior of the expandable scaffold 14 through the proximalopening 28 of the expandable scaffold 14 with the expandable scaffold 14in the expanded configuration. For example, the first balloon 52 of thefirst catheter 50 may have a first inflated diameter and the secondballoon 52 of the second catheter 50 may have a second inflated diametergreater than the inflated diameter of the first balloon 52. Thus, thefirst balloon 52 may be used to radially expand the expandable scaffoldto a first diameter and urge the cutting elements 20 into the stenosis94 a first amount, and then the first balloon 52 and catheter 50 may beexchanged for the second balloon 52 and catheter 50 to further expandthe expandable scaffold to a second diameter greater than the firstdiameter and urge the cutting elements further into the stenosis 94 asecond amount, greater than the first amount. The balloons 52 may besequentially exchanged for balloons 52 of a different size (e.g., of asequentially greater size), as desired until a desired dilatation of theblood vessel 90 has been attained.

As shown in FIG. 8, once the desired treatment of the blood vessel 90with the incising device 12 has been achieved, the incising device 12may be recaptured and retrieved with the sheath 34, and then withdrawnfrom the blood vessel 90. For example, as shown in FIG. 8, the sheath34, or another sheath, may be advanced distally to the expandablescaffold 14. The physician may grasp the elongate member 32 to hold theexpandable scaffold 14 stationary while advancing the sheath 34 distallyover the expandable scaffold 14 to collapse the expandable scaffold 14into the lumen 38 of the sheath 34, or the physician may pull theelongate member 32 proximally to pull the self-expanding scaffold 14into the distal opening 36 of the sheath 34 to collapse the expandablescaffold 14 into the lumen 38 of the sheath 34. The protective distaltip 40 of the sheath 34 may withstand scoring from the cutting elements20 as the incising device 12 is retracted into the lumen 38 through thedistal opening 36. The sheath 34 and incising device 12 may then bewithdrawn from the blood vessel 90, leaving the guidewire 30 in placefor navigating additional medical devices across the stenosis 94 in theblood vessel 90, if desired.

FIG. 9 is a side view of another exemplary medical device assembly 310for incising a stenosis in a blood vessel, or other lesion in ananatomical passage. The medical device assembly 310 may include anincising device 312 including one or more, or a plurality of cuttingelements 320 for incising or scoring a stenosis within a blood vessel.Similar to the medical device assembly 10 of FIG. 1, the medical deviceassembly 310 may also include a tubular sheath 34 for delivering theincising device 312 to the stenotic lesion in the blood vessel and/orwithdrawing the incising device 312 from the blood vessel.

The incising device 312 may be similar to the incising devise 12 in manyrespects. For example, the incising device 312 may include an expandablescaffold 314 carrying the one or more, or plurality of cutting elements320 thereon, and be configured to radially expand from a first,contracted configuration when radially constrained to a second, radiallyexpanded configuration when unconstrained. In some instances, theexpandable scaffold 314 may be a self-expanding scaffold 314 configuredto automatically radially expand from the first, contractedconfiguration when radially constrained to the second, radially expandedconfiguration when unconstrained. Thus, the self-expanding scaffold 314may be biased to the radially expanded configuration such that theself-expanding scaffold 314 tends to automatically return to theexpanded configuration when all radially constraining forces areremoved. In other instances, the expandable scaffold 314 may be expandedfrom the first, radially contracted configuration to the second radiallyexpanded configuration through the application of an expansion forceexerted by an expandable member, an expandable linkage, or otheractuatable structure for expanding the scaffold 314.

The expandable scaffold 314 may have any desired construction permittingthe expandable scaffold 314 to be radially compressed into thecontracted configuration for positioning in the lumen 38 of the sheath34, yet permitting the expandable scaffold 314 to radially expand to theexpanded configuration when unconstrained by the sheath 34. For example,as shown in FIG. 9, the expandable scaffold 314 may be formed of aunitary tubular mesh framework of interconnected struts 316, similar tothe structure of an expandable stent. At least some of theinterconnected struts 316 may extend between adjacent cutting elements320 within the tubular body portion of the expandable scaffold 314 toprovide stability between adjacent cutting elements 320. For instance,at least a portion of the interconnected struts 316 may, at least inpart, extend circumferentially around the circumference of theexpandable scaffold 314 such that interconnected struts 316 extendbetween adjacent cutting elements 320 around the tubular body portion.

The tubular mesh framework 316 may define a cylindrical body portion ofthe expandable scaffold 314. The expandable scaffold 314 may alsoinclude one or more, or a plurality of proximally extending extensionwires 322 extending from the proximal end of the tubular mesh framework316 to a proximal tubular collar 360 positionable around a tubular shaftof a balloon catheter 350. The expandable scaffold 314 may additionallyinclude one or more, or a plurality of distally extending extensionwires 323 extending from the distal end of the tubular mesh framework316 to a distal tubular collar 362 positionable around a tubular shaftof the balloon catheter 350.

The medical device assembly 310 may also include a balloon catheter 350including an inflatable balloon 352 secured to the catheter shaft 354 ofthe balloon catheter 350 at a proximal balloon waist 358 and a distalballoon waist 359. In some instances, the catheter shaft 354 may includean inner tubular member 357 defining a guidewire lumen extendingcoaxially within an outer tubular member 355, defining an annularinflation lumen therebetween for inflating the inflatable balloon 352. Ahypotube 353 may extend over a proximal portion of the outer tubularmember 355 to provide column support to the proximal portion of thecatheter shaft 354. In other embodiments, the catheter shaft 354 may beprovided with another configuration, such as first and second paralleltubular members to define a guidewire lumen and an inflation lumen,respectively.

The proximal collar 360 may surround the catheter shaft 354 proximal ofthe inflatable main portion of the balloon 352, such as around the outertubular member 355 of the catheter shaft 354 proximate to and/orproximal of the proximal balloon waist 358. Similarly, the distal collar362 may surround the catheter shaft 354 distal of the inflatable mainportion of the balloon 352, such as around the inner tubular member 357of the catheter shaft 354 proximate to and/or distal of the distalballoon waist 359. The proximal collar 360 and/or the distal collar 362may be configured to rotate and/or translate relative to the cathetershaft 354 in some instances.

The catheter 350 may also include a distal tip 356, such as an enlargeddistal tip positioned distal of the distal collar 362, and thus distalof the balloon 352 and the expandable scaffold 314 surrounding theballoon 352. In some instances, the distal tip 356 may function as adistal stop to prevent the distal collar 362 from being removed from thecatheter shaft 354. The expandable scaffold 314 may be permitted to havea limited amount of longitudinal movement relative to the catheter shaft354, as well as rotational movement about the catheter shaft 354.Movement of the proximal and distal collars 360, 362 may facilitateexpansion and contraction of the expandable scaffold 314 about theballoon 352. The distal tip 356 may have a lumen extending therethroughfor the passage of a guidewire 30. In some instances such as shown inFIG. 3A, the distal tip 356, and thus the guidewire 30 extending throughthe central lumen of the distal tip 356, may be arranged coaxially withthe expandable scaffold 314 and the balloon 352 of the balloon catheter350, with the balloon 352 coaxially positioned within the expandablescaffold 314. In some instances, the distal tip 356 may also provide anatraumatic tip to the sheath 34 when the incising device 312 isretracted into the lumen 38 of the sheath 34. Thus, in some instances,the distal tip 356, or a portion thereof, may be sized to remainexterior and distal of the sheath 34 when the expandable scaffold 314 ofthe incising device 312 is positioned within the sheath 34 duringdelivery and/or retrieval.

In some instances, the incising device 312 may also include an elongatemember 332 extending proximally from the proximal collar 360 along anexterior of the catheter shaft 354 to be manipulated by a physicianduring a medical procedure to facilitate expelling the expandablescaffold 314 from the sheath 34, drawing the expandable scaffold 314into the sheath 34, or otherwise manipulating the expandable scaffold314. The elongate member 332 and the catheter shaft 354 may extendthrough the lumen 38 of the sheath 34 to a proximal end of the medicaldevice assembly 310.

In some instances, the proximal tapered portion provided by theextension wires 322 may facilitate positioning the sheath 34 back overthe expandable scaffold 314 to radially contract the expandable scaffold314 after use of the incising device 312. For instance, the one or moreproximally extending extension wires 322 may help guide the sheath 34over the expandable scaffold 314 when collapsing the expandable scaffold314 in the sheath 34 subsequent to using the incising device 312.

The cutting elements 320 may vary in number, position, and arrangementabout the expandable scaffold 314. For example, the incising device 312may include one, two, three, four, five, six, or more cutting elements320 that are disposed at any position along the expandable scaffold 314and in a regular, irregular, or any other suitable pattern. For example,in some embodiments the incising device 312 may include a plurality ofcutting elements 320 longitudinally arranged symmetrically around thecircumference of the expandable scaffold 314.

As shown in FIG. 9A, the cutting elements 320 may be mounted to andproject radially outward from the expandable scaffold 314. In otherembodiments, the struts 316 of the expandable scaffold 314 may definethe cutting elements 320 for scoring or cutting tissue. The cuttingelements 320 may be secured to the struts 316 of the expandable scaffold314 such as by welding, brazing, soldering, crimping, adhesivelybonding, thermal bonding, or other desired means.

The balloon 352 of the balloon catheter 350 may be positioned in theinterior of the expandable scaffold 314 to provide a radially outwardforce to urge the cutting elements 320 radially outward and press thecutting elements 320 against a stenosis or other tissue. For instance,the balloon 352 of the catheter 350 may be integrally incorporated withthe incising device 312, and thus pre-inserted within the expandablescaffold 314 of the incising device 312 prior to using the incisingdevice 312 in a medical procedure. In other instances, however, theincising device 312 may be provided without a balloon 352 pre-insertedwithin the expandable scaffold 314, thus allowing a physician to selectany desired balloon 352 or other radially expandable member of acatheter 350 to be inserted within the expandable scaffold 314intra-operatively, and/or allow for exchanging between a plurality ofdifferent sizes of balloons 352 intra-operatively.

The catheter shaft 354 and sheath 34 may extend proximally to a proximalhandle assembly 380 at a proximal end of the medical device assembly 310to be manipulated by a user. The handle assembly 380 may include amanifold 382 coupled to the proximal end of the catheter shaft 354. Forexample, the proximal end of the hypotube 354, the proximal end of theouter tubular member 355 and/or the proximal end of the inner tubularmember 357 may be secured to the manifold 382, such as with an adhesive,or other bonding method. As shown in FIG. 9, the proximal end of thehypotube 353 and the proximal end of the outer tubular member 355 mayextend into the manifold 382 with the proximal end of the outer tubularmember 355 extending proximal of the proximal end of the hypotube 353.The proximal end of the inner tubular member 357 may extend proximallybeyond the proximal end of the outer tubular member 355. The manifold382 may include one or more ports, such as a guidewire port 384 incommunication with the guidewire lumen of the inner tubular member 357from which the guidewire 30 may extend from, and an inflation port 386in fluid communication with the inflation lumen between the innertubular member 357 and the outer tubular member 355 in which aninflation media may be delivered to the interior of the balloon 352through the inflation lumen.

The handle assembly 380 may also include an actuation member 388, suchas a push-pull knob or handle, coupled to the proximal end of the sheath34 for manipulation of the sheath 34 to deploy and/or retrieve theincising device 312. In other instances, the handle assembly 380 mayinclude an alternative structure configured for actuating the sheath 34.Some additional structures may include a dial, a thumb push/pull lever,or other structure to effect actuation of the sheath 34 relative to thecatheter shaft 354. A user may manipulate the actuation member 388 totranslate the sheath 34 in a proximal direction and/or a distaldirection in order to withdraw the sheath 34 from the expandablescaffold 314 and/or advance the sheath 34 over the expandable scaffold314, respectively. In some instances, the actuation member 388 mayinclude a locking mechanism to prevent inadvertent relative movementbetween the sheath 34 and the catheter shaft 354 to prevent prematuredeployment of the expandable scaffold 314 from the sheath 34. In someinstances, a distal end of the hypotube 353 may be located proximate theactuation member 388 when the sheath 34 has been pulled proximally towithdraw the sheath 34 from the expandable scaffold 314.

The medical device assembly 310, as well as the medical deviceassemblies 10, 110 and 210, may also include radiopaque marker bands 375positioned on or incorporated in various components of the assembly 310in order to permit visual observation of the assembly 310 in a bodyvessel under fluoroscopy or other visualization technique. For example,the sheath 34 may include a radiopaque marker band 375 proximate thedistal end of the sheath 34. Furthermore, the catheter shaft 356 mayinclude radiopaque marker bands 375 positioned proximal and distal ofthe balloon 352 and/or the proximal and distal collars 360, 362 mayinclude radiopaque marker bands 375 or be formed of a radiopaquematerial to facilitate positioning the incising device 312 across astenosis. Additionally, the distal tip 356 may include a radiopaquemarker band 375 or be formed of a radiopaque material in order tovisualize the position of the distal tip 356 in a vessel. Additionalradiopaque markers may be incorporated into the expandable scaffold 314or other components of the medical device assembly 310, as desired.

FIGS. 10-14 illustrate an exemplary method of treating a stenotic lesionwith the medical device assembly 310 illustrated in FIG. 9. Although theexemplary method will be described in regards to using the medicaldevice assembly 310, it is understood that such a method of treating astenosis may be performed using any of the assemblies and incisingdevice described herein, or a similarly configured incising device inaccordance with this disclosure.

The medical device assembly 310 may be navigated through the lumen 92 ofa blood vessel 90 to a treatment location proximate a stenosis 94 orother tissue to be treated which may be within any suitable peripheralor cardiac vessel lumen location. For instance, the incising device 312may be loaded in the sheath 34 with the expandable scaffold 314constrained in the contracted position within the lumen 38 of the sheath34 prior to advancing the medical device assembly 10 through the bloodvessel 90. The distal tip 356 may be located at the distal end of thesheath 34, providing an atraumatic tip for insertion of the medicaldevice assembly 310 through the vasculature.

The distal tip 356 may be inserted over a previously positionedguidewire 30, with the guidewire 30 extending through the interior ofthe expandable scaffold 314 and through the lumen 38 of the sheath 34.As shown in FIG. 10, sheath 34, with the expandable scaffold 314 of theincising device 312 positioned therein, may be advanced to the stenosis94 in the blood vessel 90. The guidewire 30 may extend through aguidewire lumen of the catheter shaft 354 of the catheter 350, whichextends within the lumen 38 of the sheath 34. The sheath 34 may beadvanced across the stenosis 94 until the expandable scaffold 314 isproperly positioned. Radiopaque marker bands 275 incorporated with thecomponents of the medical device assembly 310 may be used to visuallyconfirm the position of the expandable scaffold 314 across the stenosis94 using fluoroscopy or other visualization technique.

As shown in FIG. 11, once the radially constrained expandable scaffold314 is positioned across the stenosis 94 within the sheath 34, thesheath 34 may be withdrawn proximally to deploy the expandable scaffold314 distally from the distal opening 36 of the tubular sheath 34. Forexample, the physician may pull the actuation member 388, or otherwiseactuate the actuation member 388, to withdraw the sheath 34 proximallyto deploy the expandable scaffold 314 from the distal end of the sheath34. Radiopaque marker bands 275 incorporated with the components of themedical device assembly 310 may be used to visually confirm the positionof the distal end of the sheath 34 relative to the expandable scaffold314 to ensure of proper deployment of the expandable scaffold 314 usingfluoroscopy or other visualization technique.

The protective distal tip 40 of the sheath 34 may withstand scoring fromthe cutting elements 320 as the incising device 312 is advanced out ofthe lumen 38 through the distal opening 36. Once unconstrained by thesheath 34, the expandable scaffold 314, in instances in which thescaffold 314 is self-expandable, may automatically radially expandtoward the expanded configuration. The expandable scaffold 314 may besized such that in the expanded configuration, the cutting elements 320may contact and/or press against the stenosis 94.

As shown in FIG. 12, the deflated balloon 352 of the catheter 350,positioned within the expandable scaffold 314 can be inflated to exert aradially outward force on the interior of the expandable scaffold 314 tofurther enlarge the expandable scaffold 314 and/or to urge the cuttingelements 320 further radially outward to penetrate into or score thestenosis 94. Thus, the cutting elements 320 may cut or score thestenosis 94 to facilitate enlarging the lumen proximate the stenosis 94.Subsequently, the balloon 352 may be deflated within the interior of theexpandable scaffold 314.

As shown in FIG. 13, once the desired treatment of the blood vessel 90with the incising device 312 has been achieved, the incising device 312may be recaptured and retrieved with the sheath 34, and then withdrawnfrom the blood vessel 90. For example, as shown in FIG. 13, the sheath34, or another sheath, may be advanced distally to the expandablescaffold 314. For example, the actuation member 388 may be actuateddistally relative to the elongate shaft 354, or otherwise actuated, toadvance the sheath 34 distally over the expandable scaffold 314 and thuscollapse the expandable scaffold 314 into the lumen 38 of the sheath 34.The protective distal tip 40 of the sheath 34 may withstand scoring fromthe cutting elements 320 as the incising device 312 is retracted intothe lumen 38 through the distal opening 36.

As shown in FIG. 14, the sheath 34 may be advanced distally until theexpandable scaffold 314 is within the sheath 34 and the distal tip 356is located at the distal end of the sheath 34. Radiopaque marker bands275 may be used to visually confirm the position of the expandablescaffold 314 within the lumen 38 of the sheath 34 and/or the distal tip356 at the distal end of the sheath 34 using fluoroscopy or othervisualization technique. The sheath 34 and incising device 312 may thenbe withdrawn from the blood vessel 90, leaving the guidewire 30 in placefor navigating additional medical devices across the stenosis 94 in theblood vessel 90, if desired.

The above described features of expandable scaffolds including cuttingelements may permit the cutting elements to be delivered to a stenoticlesion in a blood vessel without being directed mounted to anangioplasty balloon. The scaffolding, with the cutting members securedthereto, may be more flexible for navigating tortuous anatomy, whilesecurely delivering the cutting elements to the treatment site.

Those skilled in the art will recognize that the present disclosure maybe manifested in a variety of forms other than the specific embodimentsdescribed and contemplated herein. Accordingly, departure in form anddetail may be made without departing from the scope and spirit of thepresent disclosure as described in the appended claims.

What is claimed is:
 1. A medical device assembly for incising a stenosisin a blood vessel, the medical device assembly comprising: aself-expanding scaffold configured to be expandable from a firstcontracted configuration to a second expanded configuration, theself-expanding scaffold being biased toward the second expandedconfiguration; a cutting element secured to the self-expanding scaffoldand extending radially outward therefrom; a sheath having a lumentherein, the self-expanding scaffold positionable in the lumen of thesheath in the first contracted configuration; and an elongate memberextending proximally from the self-expanding scaffold through the lumenof the sheath; wherein the self-expanding scaffold is constrained in thelumen of the sheath to maintain the self-expanding scaffold in the firstcontracted configuration and deployed out of the lumen of the sheath topermit the self-expanding scaffold to expand to the second expandedconfiguration.
 2. The medical device assembly of claim 1, wherein theself-expanding scaffold includes a distal tip including a guidewirelumen for receiving a guidewire therethrough, the distal tip beingarranged coaxially with the self-expanding scaffold.
 3. The medicaldevice assembly of claim 2, wherein the self-expanding scaffold isadvanceable over a guidewire positioned along an exterior surface of theelongate member and extending through the guidewire lumen of the distaltip.
 4. The medical device assembly of claim 3, wherein theself-expanding scaffold includes a proximal opening sized and configuredto advance an inflatable balloon mounted on a catheter into an interiorof the self-expanding scaffold.
 5. The medical device assembly of claim1, wherein the self-expanding scaffold includes a plurality of helicallyarranged wires crossing at cross-over points, wherein the cuttingelement is secured to the scaffold at at least one of the cross-overpoints.
 6. The medical device assembly of claim 5, wherein the pluralityof helically arranged wires converge at and are secured to a distal tipof the self-expanding scaffold.
 7. The medical device assembly of claim6, wherein the distal tip includes a guidewire lumen arranged coaxiallywith the self-expanding scaffold.
 8. The medical device assembly ofclaim 1, wherein the self-expanding scaffold includes a plurality ofhelically arranged wires extending from a distal end of the elongatemember to a distal tip of the self-expanding scaffold.
 9. The medicaldevice assembly of claim 8, wherein at least one end of the cuttingelement is slidable relative to the plurality of helically arrangedwires as the self-expanding scaffold expands from the first contractedconfiguration to the second expanded configuration.
 10. The medicaldevice assembly of claim 1: wherein the cutting element is a firstcutting element; wherein the medical device assembly further comprises asecond cutting element; and wherein the first cutting element is offsetlongitudinally relative to the second cutting element.
 11. The medicaldevice assembly of claim 1, wherein the elongate member is radiallyoffset from a central longitudinal axis of the self-expanding scaffold.12. A medical device assembly for incising a stenosis in a blood vessel,the medical device assembly comprising: an incising device including anexpandable scaffold having a plurality of cutting elements projectingradially outward therefrom, and an elongate member extending proximallyfrom the expandable scaffold to be manipulated by a user, the elongatemember being radially offset from a central longitudinal axis of theexpandable scaffold; a tubular sheath having a lumen therethrough, theexpandable scaffold positionable in the lumen of the tubular sheath in acontracted configuration with the plurality of cutting elements engagedwith an interior of the tubular sheath; and a catheter having a cathetershaft and an inflatable balloon mounted thereon, the inflatable balloonof the catheter configured to be advanced distally into an interior ofthe expandable scaffold through a proximal opening of the expandablescaffold with the catheter shaft positioned along an exterior surface ofthe elongate member; wherein inflation of the inflatable balloon urgesthe cutting elements radially outward to incise a stenosis.
 13. Themedical device assembly of claim 12, wherein the incising device isadvanceable over a guidewire positioned along an exterior surface of theelongate member.
 14. The medical device assembly of claim 13, whereinthe catheter is advanceable over the guidewire.
 15. The medical deviceassembly of claim 13, wherein the incising device includes a distal tipincluding a guidewire lumen for receiving the guidewire therethrough,the distal tip being arranged coaxially with the expandable scaffold.16. The medical device assembly of claim 15, wherein the catheterincludes a distal tip configured to contact a proximal end of the distaltip of the incising element when the inflatable balloon is properlypositioned within the interior of the expandable scaffold.
 17. Themedical device assembly of claim 12, wherein the expandable scaffoldincludes a plurality of helically arranged wires converging at andsecured to a distal tip of the incising device.
 18. A medical deviceassembly for incising a stenosis in a blood vessel, the medical deviceassembly comprising: an expandable scaffold configured to be expandablefrom a first contracted configuration to a second expandedconfiguration; a cutting element secured to the expandable scaffold andextending radially outward therefrom; and an elongate member extendingproximally from the expandable scaffold; wherein the elongate member isradially offset from a central longitudinal axis of the expandablescaffold.
 19. The medical device assembly of claim 18, wherein at leastone end of the cutting element is slidable relative to the expandablescaffold as the expandable scaffold expands from the first contractedconfiguration to the second expanded configuration.
 20. The medicaldevice assembly of claim 18: wherein the cutting element is a firstcutting element; wherein the medical device assembly further comprises asecond cutting element; and wherein the first cutting element is offsetlongitudinally relative to the second cutting element.